We introduce a isc_quota_attach_cb function - if ISC_R_QUOTA is returned
at the time the function is called, then a callback will be called when
there's quota available (with quota already attached). The callbacks are
organized as a LIFO queue in the quota structure.
It's needed for TCP client quota - with old networking code we had one
single place where tcp clients quota was processed so we could resume
accepting when the we had spare slots, but it's gone with netmgr - now
we need to notify the listener/accepter that there's quota available so
that it can resume accepting.
Remove unused isc_quota_force() function.
The isc_quote_reserve and isc_quota_release were used only internally
from the quota.c and the tests. We should not expose API we are not
using.
- if the TCP quota has been exceeded but there are no clients listening
for new connections on the interface, we can now force attachment to the
quota using isc_quota_force(), instead of carrying on with the quota not
attached.
- the TCP client quota is now referenced via a reference-counted
'ns_tcpconn' object, one of which is created whenever a client begins
listening for new connections, and attached to by members of that
client's pipeline group. when the last reference to the tcpconn
object is detached, it is freed and the TCP quota slot is released.
- reduce code duplication by adding mark_tcp_active() function
- convert counters to stdatomic
(cherry picked from commit a8dd133d270873b736c1be9bf50ebaa074f5b38f)
(cherry picked from commit 4a8fc979c49104534cf6be5d81dc54da5b6836c9)
Cleanup of redundant/useless header file inclusion.
ISC style lint, primarily for function declarations and standalone
comments -- ie, those that appear on a line without any code, which
should be written as follows:
/*
* This is a comment.
*/